Abstract: Devices, and a method for the use thereof, for the standardization of signal intensity in the formation of magnetic resonance images of the human body, said devices including one or more straight, bent or flexible closed tubes with an external diameter not greater than 3 cm, an internal diameter of not less than 0.2 cm and a length of not less than 8 cm, made of susbtantially diamagnetic material, other than glass, preferably a plastic material, particularly polyvinyl chloride, each of them being filled with aqueous solutions or gels containing paramagnetic components, said tubes being kept close to the body either by means of the positioning devices of the body to which they are fixed permanently or temporarily, or by fixings which, on one side, can be fixed to the human body and on the other keep the tubes in the required positior.

Abstract: The present invention relates to a process for the preparation of injectable solutions of pharmaceutical products and/or of diagnostic agents, characterized by an extremely high degree of purity as regards the low content of bacterial endotoxins. The process of the invention provides for the prefiltering of the solutions by means of a microfiltering unit, a subsequent ultrafiltration and the recycling of the retentate from the ultrafiltration to the solution which emerges from the prefilter.